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Nakamura, Shoji; Endo, Shunsuke; Kimura, Atsushi; Shibahara, Yuji*
KURNS Progress Report 2022, P. 73, 2023/07
The present study is concerned with the neutron capture cross-sections that contribute to the evaluation of the amount of radionuclides possessing problems in decommissioning. In this study, 
Sc, 
Cu, 
Zn, 
Ag, 
In and 
W were selected among the objective nuclides, and their thermal-neutron capture cross-sections were measured using TC-Pn equipment of the KUR of the Institute for Integrated Radiation and Nuclear Science, Kyoto University. High purity metal samples were prepared. A gold-aluminum ally wire, cobalt and molybdenum foils were used to monitor the neutron flux at the irradiation position of TC-Pn. The flux monitors and metal samples were irradiated for 1 hour at 1-MW operation of the KUR. After irradiation, the irradiation capsule was opened, samples and flux monitors were enclosed in a vinyl bag one by one, and then 
rays emitted from the samples and monitors were measured with a high-purity Ge detector. The thermal-neutron flux component was derived with the reaction rates of flux monitors (
Au, 
Co and 
Mo) on the basis of Westcott's convention, and found to be (5.92
0.10)
10
n/cm
/sec at the irradiation position. The measured reaction rate for each metal sample divided by the evaluated thermal-neutron capture cross-section should give the same value of the thermal-neutron flux component if the cross section is suitable. This time, we found that the cross sections of Sc and 
Zn were consistent with the evaluated one, but those of other nuclides were inconsistent with their evaluated ones; that is, it turned out that their thermal-neutron capture cross-sections should be modified.
Nakamura, Shoji; Hatsukawa, Yuichi*; Kimura, Atsushi; Toh, Yosuke; Harada, Hideo
Journal of Nuclear Science and Technology, 58(12), p.1318 - 1329, 2021/12
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)The present study performed fast-neutron capture cross-section measurement of 
Tc by an activation method using a fast-neutron source reactor "YAYOI" of the University of Tokyo. Technetium-99 samples were irradiated with reactor neutrons using a pneumatic system. Reaction rates of Tc were obtained by measuring decay gamma rays emitted from 
Tc. The neutron flux at an irradiation position was monitored with gold foils. The fast-neutron capture cross section of Tc at neutron energy of 85 keV was derived as 0.4320.023 barn by using the reaction rates of Tc, evaluated cross-section data and the fast-neutron flux spectrum of the YAYOI reactor. The present study agreed with the evaluated nuclear data library JENDL-4.0.
-process nucleosynthesisBhattacharyya, A.*; Datta, U.*; Rahaman, A.*; Chakraborty, S.*; Aumann, T.*; Beceiro-Novo, S.*; Boretzky, K.*; Caesar, C.*; Carlson, B. V.*; Catford, W. N.*; et al.
Physical Review C, 104(4), p.045801_1 - 045801_14, 2021/10
Times Cited Count：5 Percentile：57.13(Physics, Nuclear)no abstracts in English
Np using graphite thermal columnNakamura, Shoji; Endo, Shunsuke; Kimura, Atsushi; Shibahara, Yuji*
KURNS Progress Report 2020, P. 94, 2021/08
The present study selected Np among radioactive nuclides and aimed to converge a contradiction between reported thermal-neutron capture cross sections. Neutron irradiation was carried out using the graphite thermal column equipped with the Kyoto University Research Reactor. A solution equivalent to 950 Bq order of radioactivity was pipetted out of a Np standard solution and dropped onto a fiber filter, which was then dried with an infrared lamp to prepare a Np sample. The Np sample was quantified using 312-keV gamma ray emitted from 
Pa in a radiation equilibrium with Np. To monitor a thermal-neutron flux component at an irradiation position, the Np sample was irradiated together with several stable nuclides as neutron flux monitors: Sc, Co, Mo, 
Ta and Au. The reaction rate of Np was obtained from gamma-ray yields given by 
Np and Pa, and then the thermal-neutron capture cross section of Np was derived.
P
rez S
nchez, R.*; Jurado, B.*; Mot, V.*; Roig, O.*; Dupuis, M.*; Bouland, O.*; Denis-Petit, D.*; Marini, P.*; Mathieu, L.*; Tsekhanovich, I.*; et al.
Physical Review Letters, 125(12), p.122502_1 - 122502_5, 2020/09
Times Cited Count：13 Percentile：70.32(Physics, Multidisciplinary)Nakamura, Shoji; Terada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Iwamoto, Osamu; Harada, Hideo; Uehara, Akihiro*; Takamiya, Koichi*; Fujii, Toshiyuki*
Journal of Nuclear Science and Technology, 56(1), p.123 - 129, 2019/01
Times Cited Count：1 Percentile：11.15(Nuclear Science & Technology)Accurate data of -ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by -ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces 
Am after neutron capture. The 744-keV -ray decaying from the ground state of Am has a relatively large -ray emission probability c.a. 66%, however, its uncertainty is as large as 29%. The uncertainty of the -ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the -ray emission probability was measured by using an activation method and an examined level structure of Cm. In this study, the emission probability of 744-keV ray was derived as 66.51.1%, and its uncertainty was improved from 29% to 2%.
Nakao, Taro; Terada, Kazushi; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; Hori, Junichi*
EPJ Web of Conferences, 146, p.03021_1 - 03021_4, 2017/09
Times Cited Count：7 Percentile：96.32(Nuclear Science & Technology)A new data acquisition system (DAQ system) in J-PARC Materials and Life Science Experimental Facility (MLF) ANNRI was developed. Increasing beam power of MLF in recent years allows beam line users to obtain high quantity experimental data yields. Compared to 2008, more than 20 times beam current is achieved in 2015. For the purpose to correspond strong beam power of MLF, a new DAQ system for the array of the Ge detectors in ANNRI is developed. The DAQ system is also going to be used for processing signals from a Li glass detector, which is under development at ANNRI for measurement of total neutron cross sections. Commissioning experiment of a new DAQ system at ANNRI was performed by using 0.1mmt Au sample with 500kW J-PARC proton beam power. An applicability of time-of-flight method for both neutron capture and total cross-sections measurements was checked. ADC and TDC nonlinearity, energy resolution, multi-channel coincidence and dead time performance for the array of the Ge detectors were also evaluated. The dead time value for Ge detectors was successfully decreased to 1/4 from the previous DAQ system with minor deterioration on energy resolution. The author would like to thank the accelerator and technical staff at J-PARC for operation of the accelerator and the neutron production target and for the other experimental supports. Present study includes the result of "Research and Development for accuracy improvement of neutron nuclear data on minor actinides" entrusted to the Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).
Cs(n,) cross-section using a New DAQ System at ANNRIHales, B. P.; Nakamura, Shoji; Kimura, Atsushi; Iwamoto, Osamu
J-PARC 17-07; J-PARC MLF Annual Report 2016, p.88 - 89, 2017/03
Zr(n,)Zr cross section with 
Zr(
O,
O)
Zr reactionsYan, S. Q.*; Li, Z. H.*; Wang, Y. B.*; Nishio, Katsuhisa; Makii, Hiroyuki; Su, J.*; Li, Y. J.*; Nishinaka, Ichiro; Hirose, Kentaro; Han, Y. L.*; et al.
Physical Review C, 94(1), p.015804_1 - 015804_5, 2016/07
Times Cited Count：6 Percentile：44.49(Physics, Nuclear)
PdNakamura, Shoji; Kimura, Atsushi; Toh, Yosuke; Harada, Hideo; Katabuchi, Tatsuya*; Mizumoto, Motoharu*; Igashira, Masayuki*; Hori, Junichi*; Kino, Koichi*
JAEA-Conf 2015-003, p.113 - 118, 2016/03
Experiments were carried out with the Ge detector of ANNRI to confirm whether or not the weak resonances were surely due to Pd. The prompt rays due to capture reaction of Pd were clearly observed at the -ray energy at 115 kev and around 300 keV. When a TOF spectrum was extracted by gating at the prompt ray around 300 keV, the small resonance peaks were revealed at the neutron energy of 146 and 156 eV.
Harada, Hideo
Kaku Deta Nyusu (Internet), (109), p.44 - 47, 2014/10
Improvement of accuracy of neutron nuclear data for minor actinides (MAs) and long-lived fission products (LLFPs) is required for developing innovative nuclear system transmuting these nuclei. In order to meet the requirement, the project entitled as "Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides (AIMAC)" has been started as one of the "Innovative Nuclear Research and Development Program". The AIMAC project team is composed of researchers in four different fields: differential nuclear data measurement, integral nuclear data measurement, nuclear chemistry, and nuclear data evaluation. By integrating all of the forefront knowledge and techniques in these fields, the research project team aims at improving the accuracy of the data. The background, goal and brief research plan of the AIMAC project are explained.
Ge spectrometer by Geant4Goto, Jun; Sugawara, Masahiko*; Oshima, Masumi; Toh, Yosuke; Kimura, Atsushi; Osa, Akihiko; Koizumi, Mitsuo; Mizumoto, Motoharu; Osaki, Toshiro*; Igashira, Masayuki*; et al.
AIP Conference Proceedings 769, p.788 - 791, 2005/05
no abstracts in English
Re isomeric stateHayakawa, Takehito; Shizuma, Toshiyuki; Yamauchi, Toshihiko; Minehara, Eisuke; Arisawa, Takashi
Nuclear Physics A, 718, p.665c - 667c, 2003/05
no abstracts in English
Nakagawa, Tsuneo; Iwamoto, Osamu
JAERI-Data/Code 2002-025, 134 Pages, 2003/01
JAERI-Data-Code-2002-025.pdf:3.48MB
no abstracts in English
; Sato, Wakaei*; Iwai, Takehiko*
JNC TN9400 2000-096, 113 Pages, 2000/06
This report describes the updated analyses results on the BFS-58-1-I1 core. The experiment was conducted at BFS-2 of Russian Institute of Physics & Power Engineering (IPPE). The central region is "non-Uranium fuel zone", where only Pu can induce fission reaction. The non-U zone is surrounded by MOx fuel zone, which is surrounded by U0
fuel zone. Sodium is used for simulating the coolant material. As it was found that the lattice pitch had been incorrectly understood in the past analyses, all items have been re-calculated using the corrected number densities. Furthermore, significantly softened neutron spectrum in the central region caused problems in applying the plate-stretch model that has been established for fast reactor cores through JUPITER experimental analyses. Both keeping the pellet density and using SRAC library for the elastic cross section for lighter nuclides allow us to obtain reasonable analysis accuracy on the spectral indices that were measured at the center of the core. Application of such a cell model was justified through comparison among various cell models using continuous energy Monte-Carlo code MVP. It is confirmed that both the MOX zone and the U0 zone can be correctly evaluated by the plate-stretch model. Based on the updated cell calculation, both the effective multiplication factor (k-eff)and the spectral indexes agree well with the measured values. The transport and mesh-size correction is made for the k-eff evaluation. Those results also agree well within reasonable difference between those obtained by IPPE and CEA, which were obtained by using sub-group method or continuous-energy Monte Carlo code. Evaluation by the nuclear data library adjustment confirmed that the analyses results of the BFS-58-1-I1 core have no significant inconsistency with JUPITER experimental analyses results. Those results are quite important for starting BFS-62 cores, which will be analyzed in the framework of supporting program for Russian ...
*
JNC TJ9400 2000-009, 63 Pages, 2000/02
JNC-TJ9400-2000-009.pdf:2.48MB
The present status of nuclear data for technetium (Tc)-99, which is a well-known fission product (FP), has been reviewed and investigated. And making use of the Kyoto university Lead Slowing-down Spectrometer (KULS), the cross section of the Tc (n, ) Tc reaction has been measured in the energy range from thermal to keV neutron energy with an Ar-gas proportinal counter. The neutron flux/spectrum has been monitored with a BF
proportional counter, and the relative measurement has been normalized to the well-known standard capture cross section value for the Tc (n, ) Tc reaction at 0.0253 eV. Self-shielding corrections, especially near the resonance peaks, were made by the calculations with the MCNP code. Although the experimental data measured by Chou et al with a lead slowing-down spectrometer are higher in general, the energy dependency is similar to the present measurement. The evaluated data in ENDF/B-VI and JENDL-3.2 are higher near the resonances at 5.6 and 20 eV and above several 100 eV. A lead slowing-down spectrometer was installed coupled to a 46 MeV electron linac at the Research Reactor Institute, Kyoto university (KURRI). Characteristics of the Kyoto University Lead Slowing-down Spectrometer (KULS) were measured and (1)the relation between neutron slowing-down time t(
s) and energy E(keV) (E=190/t in Bi hole and E=156/t in Pb hole) and (2)the energy resolution (
40% in Bi and Pb holes) were experimentally investigated. (3)The neutron energy spectrum in the KULS was also measured by the neutron TOF method. The results obtained by the MCNP code were in general agreement with these experimental ones.
*
JNC TJ9400 2000-008, 61 Pages, 2000/02
For studies on nuclear transmutation of long-lived fission products (LLFPs) in a fast reactor, detailed characteristics of reactor core such as transmutation performance have to be investigated, so accurate neutron cross section data of LLFPs become necessary. Therefore, the keV-neutron capture cross sections of Tc-99, which is one of important LLFPs, were measured in the present study to obtain the accurate data. The measurement was relative to the standard capture cross sections of Au-197. A neutron time-of-flight method was adopted with a ns-pulsed neutron source by a Pelletron accelerator and a large anti-Compton NaI(TI) gamma-ray detector. As a result, the capture cross sections of Tc-99 were obtained with the error of about 5 % in the incident neutlon energy region of 10 to 600 keV. The present data were compared with other experimental data and the evaluated values of JENDL-3.2, and it was found that the evaluations of JENDL-3.2 were 15-20 % smaller than the present measurements.
*; *
JNC TJ9400 2000-004, 109 Pages, 2000/02
JNC-TJ9400-2000-004.pdf:4.96MB
We estimated covariances of the JENDL-3.2 data on the nuclides and reactions needed to analyze fast-reactor cores for the past three years, and produced covariance files. The present work was undertaken to re-examine the covariance files and to make some improvements. The covariances improved are the ones for the inelastic scattering cross section of O, the total cross section of 
Na, the fission cross section of 
U, the capture cross section of U, and the resolved resonance parameters for U. Moreover, the covariances of U data were newly estimated by the present work. The covariances obtained were compiled in the ENDF-6 format.
Nakagawa, Tsuneo; Chiba, Satoshi; Osaki, Toshiro*; Igashira, Masayuki*
JAERI-Research 2000-002, p.93 - 0, 2000/02
JAERI-Research-2000-002.pdf:4.41MB
no abstracts in English
Z.Pintai*; Takano, Hideki
JAERI-Research 96-010, 72 Pages, 1996/03
JAERI-Research-96-010.pdf:2.01MB
no abstracts in English
